To address recent rapid increase in traffic, it is urgent that wireless access capabilities are improved. To realize a high-speed and large-capacity wireless access network, it is studied to arrange a macro cell in which a relatively low frequency of an ultra-high frequency (UHF) band is used and a small cell in which a relatively high frequency is used in an overlay manner. Further, in a small cell in which a high frequency band is used, it is studied to utilize full-dimension multiple-input and multiple-output (FD-MIMO) which compensates for a large propagation loss.
For example, a transmitting apparatus can transmit a sharp beam in accordance with a location of a receiving apparatus by using an array antenna in which a number of antenna elements are two-dimensionally arranged. In order to form an appropriate beam in accordance with a location, for example, a technology of transmitting a reference signal and feeding back a measurement result has been developed.
For example, the following Patent Literature 1 discloses a technology in which an eNB transmits a UE-specific demodulation reference signal (DM-RS) to the UE in a radio resource domain for downlink data signals, and the UE measures channel quality information on the basis of the DM-RS and reports the channel quality information to the eNB.
Further, the following Non-Patent Literature 1 discloses a UE-specific CSI-RS.